The pilot suffered a concussion and reported he has no recall of the events associated with the accident. The pilot rated passenger stated the pilot entered left downwind for runway 17. The passenger stated in his opinion the airplane was high and fast when the pilot turned the airplane on final approach. The pilot initiated a slip to the left to lose altitude and the airplane was crabbing to the left. The left wing of the airplane collided with a tree about 10-feet in the air and came to rest on the ground. The passenger stated the airplane did not experienced a mechanical malfunction during the approach for landing. Examination of the airplane by the FAA revealed the airplane received structural damage to both wings and the airframe. The flaps were found in the full down position. The left and right main fuel tanks contained between 30 to 40 gallons of 100-low lead fuel. No anomalies were noted with the engine assembly. Examination of runway 17 revealed the airplane collided with trees left wing low about 15 to 16 above the ground and about 50 feet left of runway 17. The airplane continued forward an additional 50-feet with the airplane striking numerous trees. The right wing tip collided with the ground and separated the right wing tip. The airplane continued forward an additional 20 feet, collided with a tree, separated the outboard 5-feet of the right wing, and came to a complete stop off the left side of the runway in the trees.